Home-made wind generator and its industrial analogues

Theory, practice, the current model of a wind generator and its industrial analogues with a description and price.

For those who often travels and stops for days and nights out in nature, it probably occurred to me that it would be nice to have a recharge source for a car battery and batteries of other mobile devices: laptops, phones, gps navigators, lights, etc.

In addition, having a sufficiently powerful energy source of even 12 V, you can use a voltage converter 12 220 to get a full-fledged 220 V socket. This will further increase the level of comfort that all citizens are used to and increase the number of devices used to their usual level.

You can get this level of comfort with solar panels, wind generators and hydrogenerators. With a power level of up to 1000 W, these devices can be compact enough even for carrying by one person, if we talk about vehicles, then you can take with you more powerful energy sources.

Where to begin?

If you have the skill to work with simple tools, such as a “grinder”, an electric drill, a welding machine, soldering iron, screwdriver, then it will not be difficult for you to assemble a homemade windmill. But remember that, as in any business, skill comes with experience. It is one thing to assemble an existing layout and a completely different windmill designed for any wind, with voltage stabilization and protection against overloads.

Now let’s dwell in more detail on how to assemble a simple windmill and what is needed for this. It should be said that there are windmills of horizontal and vertical type, i.e. with the plane of rotation of the rotor in the vertical and horizontal plane.

The most widely used historically windmills, with vertically located rotors (windmills). This is somewhat strange, if you recall that horizontal has several obvious advantages. For example, they are all-perspective, i.e. wind from either side will rotate their rotor. They only need one bearing.

“Vertical” windmills need the same rotary device, tail to track the wind and turn in the wind. In addition, they need an additional bearing to rotate the working rotor and another hinge to protect against too strong winds.

Heart of a windmill.

In the beginning, during the construction of a windmill, it is necessary to determine electric generator. This is the heart of your device. The first thing that comes to mind is car generator. But we must take into account some nuances.

Firstly, automobile generators require excitation voltage, i.e. requires an additional wire to connect and an additional battery to run, which is not very convenient.

Secondly, automobile generators require a high rotation speed for efficient operation (more than 1000 rpm), which complicates the drive.

Thirdly, they are quite heavy, which complicates the design of the mast.

Based on the foregoing, as a working generator, usually choose DC motors. If you spin such an engine by the working shaft, then voltage will appear on its terminals.

Well-proven electric motors from ancient computers of the middle of the last century. In these devices, they rotated drives of drives and tape drives. Such engines can be found on the Mitino radio market in Moscow, or at another flea market.

The current model.

The particular engine used had the following parameters: U = 48 V, I = 15A, N = 1200 rpm. The rotor of a wind turbine rotates at a frequency of about 500 rpm, and with increasing frequency, it is not the voltage that increases, but the operating current.

To optimize the operation of the device, the working rotor is not mounted on the motor shaft, but a gearbox is used.The gearbox can be either chain or belt. The chain is much more reliable, and the belt is easier to manufacture.

Applied chain. As a drive, you can use the "mechanics" from the old bike and pipes from its frame. On the rotor there is an asterisk Z = 48, on the generator Z = 10, the connection is made by a bicycle chain.

The generator is fastened with bolts, but you can use a piece of plastic pipe by first inserting the generator into it and securing it with car screw clamps. It is better to fill the places of fastening of bolts and clamps with rubber glue “Moment”.

The nuances of manufacturing a rotor.

It is very responsible to approach the manufacture of the rotor. The efficiency of the generator depends very much on its quality. The rotor after manufacturing must be carefully balanced. The lifetime of the entire device depends on this.

The blades are made of 2 mm aluminum or plastic pipes with a diameter of 60-80 mm. It’s easier to make pipes, because this material is softer and easier to give the desired profile. You may need to experimentally resize the blades.

Large and wide blades work in very weak winds, but do not develop high revolutions due to the high aerodynamic drag. Small ones spin quickly, but with a sufficiently strong wind.

My windmill has a rotor with a diameter of 2.5 meters, with a weak wind (5-8m / s) 6 blades are used. With a strong wind, four blades are removed, even with two blades the windmill gives 4-6 A at a voltage of 14 V.

You can reduce the size of the rotor to 1.6 and use 2-3 blades constantly. If you intend to change the number of blades depending on the strength of the wind, then the mast must be made with a hinge at the base so that it can be lowered without folding.

How to make a mast?

The mast is made of several sections 2-2.5 meters long from a ¾ inch steel pipe or from an aluminum pipe, but with a larger diameter. Usually 3-4 sections are used, so they are easier to mount and transport. To prevent your mast from falling, you need to use a “heel” in the form of a metal rectangle of 30x30 cm and a system of three extensions with metal pegs. You can use a ready-made mast, for example, which is used for antennas of the microwave range. Very comfortable professional telescopic masts are also for sale.

Strong wind protection.

A few words about overload protection in very strong winds. The simplest option is an additional hinge on the mast. With the help of this hinge, a windmill can itself tip over, "lifting" the rotor into the sky, with a very strong wind, or you yourself can overturn it using a rope tied to the "tail" of the windmill. By the way, the tail is made of a pipe or corner with a vertical blade attached at the end, measuring approximately 50x50 cm. The total length of the tail is approximately 1.8 m.

Remote Control.

The battery control and charging panel contains, in its simplest form, a 30 V voltmeter; ammeter at 30 A; diode bridge for 30 A 100 V; ballast wirewound resistor with an engine (rheostat) at 50 W, resistance 5-10 Ohms. The resistor is finalized by removing the last few turns.

After refinement, if you move the resistor slider to its extreme position, its circuit will be open. This is his working condition. The resistor is turned on in parallel with the generator before the diode bridge, but after the ammeter. It is used to emergency stop the generator (reduce the rotor speed).

Electrical methods of protection and control.

The resistor must withstand a current of 20-30 A for 30 seconds. If the battery is already fully charged and there is no need to turn on additional loads, then we short-circuit the generator with a resistor within a few seconds. The current in this case is 2-3 times less than the working one.

After stopping, we “overturn” the generator or tie one of the blades to the mast. Never stop the generator blades with your hands or with foreign objects, as this always leads to personal injury and equipment damage.

Do not limit the charging current of the battery with a resistor, asthis is likely to lead to its failure. To limit the current, use additional loads, usually incandescent lamps. To connect the generator and the control system, a conventional cable without sliding rings is used. Cable cross section 2x2.5 square millimeters. The best material is rubber or silicone.

Voltage converter 12-220 V.

Purchased devices are usually used as 12-220 V inverters, but they are quite expensive (from 1,500 to 10,000 rubles). For such purposes, you can use decommissioned office "uninterruptible" UPS 1000-UPS 5000. After a year of operation, their batteries no longer “hold” the load. Such devices are discarded and disposed of in the trash. By connecting a car battery to the UPS, you get a beautiful inverter for free.